Vehicle seat

ABSTRACT

To reduce an amount of rear protrusion of a vehicle seat equipped with an airbag module configured to deploy rearward, in a vehicle seat (1) provided with a seat cushion (3) and a seat back (4), the seat back includes: a seat back frame (7) including a pair of left and right side frames (11) extending in a vertical direction and an upper frame (12) connecting upper ends of the side frames to each other; an airbag module (43) supported by an upper half of the seat back frame via a bracket (31); and a skin member (9) covering the seat back frame, the bracket, and the airbag module from a rear side thereof, wherein a part of the skin member corresponding to the airbag module is provided with a frangible portion (80) configured to open upon inflation of an airbag (45).

CROSS REFERENCE TO RELATED APPLICATIONS

This application is the U.S. National Stage entry of InternationalApplication Number PCT/JP2018/014053 filed under the Patent CooperationTreaty having a filing date of Apr. 2, 2018, which claims priority toJapanese Patent Application No. 2017-152508 having a filing date of Aug.7, 2017, Japanese Patent Application No. 2017-152514 having a filingdate of Aug. 7, 2017, Japanese Patent Application No. 2017-152522 havinga filing date of Aug. 7, 2017, and Japanese Patent Application No.2017-152525 having a filing date of Aug. 7, 2017, which are incorporatedherein by reference.

TECHNICAL FIELD

The present invention relates to a front vehicle seat equipped with anairbag.

BACKGROUND ART

In some vehicles, a front vehicle seat is equipped with an airbag moduleconfigured to deploy rearward (see Patent Document 1, for example). Insuch a vehicle seat, the airbag module is mounted on the rear face ofthe seat back such that, at the time of a frontal collision, the airbagthat deploys rearward protects an occupant seated in the rear seat.

PRIOR ART DOCUMENT(S) Patent Document(s)

-   Patent Document 1: JPH06-87060U

SUMMARY OF THE INVENTION Task to be Accomplished by the Invention

There is a problem that the airbag module protrudes rearward of the seatback, and hence, it is difficult to ensure a space between the frontseat and the rear seat.

In view of the above background, an object of the present invention isto provide a vehicle seat in which an airbag module configured to deployrearward is installed and the airbag module is housed in the seat back.

Means to Accomplish the Task

To achieve the above object, there is provided a vehicle seat (1)provided with a seat cushion (3) and a seat back (4), wherein the seatback comprises: a seat back frame (7) including a pair of left and rightside frames (11) extending in a vertical direction and an upper frame(12) connecting upper ends of the side frames to each other; an airbagmodule (43) supported by an upper half of the seat back frame via abracket (31); and a skin member (9) covering the seat back frame, thebracket, and the airbag module from a rear side thereof, and wherein apart of the skin member corresponding to the airbag module is providedwith a frangible portion (80) configured to open upon inflation of anairbag (45).

According to this aspect, the airbag module is covered by the skinmember covering the seat back frame, and therefore, it is possible tohouse airbag module in the seat back. Further, since the skin membercovering the airbag module from the rear side is formed with a frangibleportion, the airbag is allowed to deploy rearward.

In the above aspect, preferably, the airbag module is located at aposition below the upper frame and overlapping with the side frames inside view.

According to this aspect, since the airbag module is located at aposition overlapping with the side frames in side view, the amount ofrearward protrusion of the seat back can be reduced.

In the above aspect, preferably, the bracket is located more rearwardthan a headrest pillar (28).

According to this aspect, the bracket can be provided without changingthe position of the headrest pillar.

In the above aspect, preferably, the bracket consists of a plate memberdefining a recess (41) for housing the airbag module, and a bottom wall(42) of the recess has a flat plate-like shape inclined rearward in adownward direction with respect to an axial direction of the headrestpillar.

According to this aspect, since the bottom wall of the recess formed inthe bracket is inclined rearward from up to down, discomfort felt in theback of the seated occupant due to the bracket can be reduced.

In the above aspect, preferably, the bracket is joined to the upperframe at an upper edge thereof and is joined to the respective sideframes at left and right edges thereof.

According to this aspect, the bracket can support the airbag moduleagainst the load caused by deployment of the airbag.

In the above aspect, preferably, a lower edge of the bracket is providedwith a rim wall (36) that protrudes forward, and the bracket is joinedto the side frames at a part of the bracket between the rim wall and alower end of the recess with respect to a vertical direction.

According to this aspect, it is possible to increase the stiffness ofthe bracket. Because the side frames are joined to each other via thebracket having high stiffness, the stiffness of the seat back frame as awhole can be increased.

In the above aspect, preferably, an upper edge of the bracket isprovided with a pair of upper tongues (34) protruding in a laterallyspaced relationship, and upper ends of the upper tongues are joined tothe upper frame.

According to this aspect, the joint between the bracket and the upperframe becomes more firm.

In the above aspect, preferably, the bottom wall of the recess is formedwith a through-hole (51) and the airbag module is fastened to the bottomwall by a fastener (50) passed through the through-hole.

According to this aspect, the bottom wall of the recess can support theforward load applied to the bracket upon deployment of the airbag.

In the above aspect, preferably, a lower side wall of the recess isformed with a through-hole (51) and the airbag module is fastened to thelower side wall of the recess via a fastener (50) passed through thethrough-hole.

According to this aspect, the fastener does not protrude forward, anddiscomfort felt in the back of the seated occupant can be reduced.

In the above aspect, preferably, the bracket is located above a pressurereceiving member (17) configured to support a back of an occupant.

According to this aspect, it is possible to prevent the bracket fromcausing discomfort felt in the back of the occupant.

In the above aspect, preferably, a blower (56) for blowing air isprovided on a front face of the bracket.

According to this aspect, it is unnecessary to provide a bracket forsupporting the blower within the vehicle seat, whereby the vehicle seatcan be simplified.

In the above aspect, preferably, the airbag module includes the airbag,an inflator disposed below the airbag and configured to inflate theairbag, and a retainer that houses the airbag and the inflator and opensrearward, the retainer includes a guide wall that opposes the inflatorat a position above the airbag and faces downward, and the airbag isguided by the guide wall to inflate rearward.

According to this aspect, the guide wall can guide the airbag to inflaterearward, whereby it is possible to make the airbag deploy to the rearof the seat back.

In the above aspect, preferably, the frangible portion is locatedsubstantially behind the guide wall.

According to this aspect, the airbag is guided by the guide wall toinflate toward the frangible portion, whereby a load is likely to beapplied to the seam.

In the above aspect, preferably, at least a part of the frangibleportion overlaps with the bracket in rear view and the airbag module isprovided on a rear face of the bracket.

According to this aspect, because the frangible portion overlaps withthe bracket in rear view, the airbag can pass the frangible portioneasily, and thus, the airbag can easily deploy to the rear of the seatback. Further, at the time of airbag deployment or when the occupantseated in the rear seat collides with the airbag, the airbag module canbe supported by the bracket.

In the above aspect, preferably, the frangible portion extendslaterally, and at least one of a first stay cloth having a base endjoined to the bracket at a position above the airbag module in side viewand a free end joined to a vicinity of a part of the skin member abovethe frangible portion and a second stay cloth having a base end joinedto the bracket at a position below the airbag module in side view and afree end joined to a vicinity of a part of the skin member below thefrangible portion is provided.

According to this aspect, the airbag module is covered by the skinmember together with the seat back frame, and the airbag module isaccommodated inside the seat back. In addition, at least one of thefirst stay cloth and the second stay cloth transmits the load caused bythe inflation of the airbag to the frangible portion so that thefrangible portion opens, whereby the airbag is allowed to deploy to therear of the seat back through the frangible portion.

In the above aspect, preferably, a pad member provided at a rear of theairbag module is located between the airbag module and the skin member,and the pad member is provided with a first slit (71) extending from arear of a deployment port of the airbag module to a front of thefrangible portion.

According to this aspect, it is possible to make the airbag deploy tothe rear of the seat back. Since the airbag module can be covered by thepad member, the touch feeling of the rear face of the vehicle seat isimproved.

In the above aspect, preferably, the pad member is provided with asecond slit (72) extending from a rear of a joint between the bracketand the base end of the first stay cloth to the front of the frangibleportion such that the first stay cloth is passed therethrough.

According to this aspect, the length of the first stay cloth in thefore-and-aft direction can be reduced, and therefore, the load appliedto the first stay cloth is easily transmitted to the frangible portionand this facilitates the opening of the frangible portion.

In the above aspect, preferably, the second stay cloth extends along alower edge and a rear edge of the pad member to reach a vicinity of thepart below the frangible portion.

According to this aspect, the second stay cloth can be attached easily.

In the above aspect, preferably, the bracket is in a plate-like shapehaving a main surface facing rearward and includes a rim wall (36)protruding forward at a lower edge thereof, and a hooking member (84)hooked by the rim wall is joined to the base end of the second staycloth.

According to this aspect, the second stay cloth can be joined to thebracket easily.

In the above aspect, preferably, the bracket includes an engagementportion (55) above the airbag module, and an engaged member (83) engagedby the engagement portion is joined to the base end of the first staycloth.

According to this aspect, the first stay cloth can be joined to thebracket easily.

Effects of the Invention

According to the foregoing aspects, it is possible to provide a vehicleseat in which an airbag module configured to deploy rearward isinstalled and the airbag module is housed in the seat back.

Also, according to the aspect wherein the airbag module is located at aposition overlapping with the side frames in side view, the amount ofrearward protrusion of the seat back can be reduced.

Also, according to the aspect wherein the bracket is located morerearward than a headrest pillar, the bracket can be provided withoutchanging the position of the headrest pillar.

Also, according to the aspect wherein the bottom wall of the recessformed in the bracket is inclined rearward from up to down, discomfortfelt in the back of the seated occupant due to the bracket can bereduced.

Also, according to the aspect wherein the bracket is joined to the upperframe at an upper edge thereof and is joined to the respective sideframes at left and right edges thereof, the bracket can support theairbag module against the load caused by deployment of the airbag.

Also, according to the aspect wherein a lower edge of the bracket isprovided with a rim wall that protrudes forward, it is possible toincrease the stiffness of the bracket. Because the side frames arejoined to each other via the bracket having high stiffness, thestiffness of the seat back frame as a whole can be increased.

Also, according to the aspect wherein upper ends of the pair of uppertongues provided on the bracket are joined to the upper frame, the jointbetween the bracket and the upper frame becomes more firm.

Also, according to the aspect wherein the bottom wall of the recess isformed with a through-hole and the airbag module is fastened to thebottom wall by a fastener passed through the through-hole, the bottomwall of the recess can support the forward load applied upon deploymentof the airbag.

Also, according to the aspect wherein a lower side wall of the recess isformed with a through-hole and the airbag module is fastened to thelower side wall of the recess via a fastener passed through thethrough-hole, the fastener does not protrude forward, and discomfortfelt in the back of the seated occupant can be reduced.

Also, according to the aspect wherein the bracket is located above apressure receiving member (17) configured to support a back of anoccupant, it is possible to prevent the bracket from causing discomfortfelt in the back of the occupant.

Also, according to the aspect wherein a blower for blowing air isprovided on a front face of the bracket, it is unnecessary to provide abracket for supporting the blower within the vehicle seat, whereby thevehicle seat can be simplified.

Also, according to the aspect wherein the airbag module includes theairbag, an inflator configured to inflate the airbag, and a retainerprovided with a guide wall that faces downward, and the airbag is guidedby the guide wall to inflate rearward, it is possible to make the airbagdeploy to the rear of the seat back.

Also, according to the aspect wherein the frangible portion is locatedsubstantially behind the guide wall, the airbag is guided by the guidewall to inflate toward the frangible portion, whereby a load is appliedto the frangible portion easily.

Also, according to the aspect wherein at least a part of the frangibleportion overlaps with the bracket in rear view and the airbag module isprovided on a rear face of the bracket, because the frangible portionoverlaps with the bracket in rear view, the airbag can pass thefrangible portion easily, and thus, the airbag can easily deploy to therear of the seat back. Further, at the time of airbag deployment or whenthe occupant seated in the rear seat collides with the airbag, theairbag module can be supported by the bracket.

Also, according to the aspect wherein the frangible portion extendslaterally, and at least one of a first stay cloth and a second staycloth is provided, the airbag module is covered by the skin membertogether with the seat back frame, and the airbag module is accommodatedinside the seat back. In addition, at least one of the first stay clothand the second stay cloth transmits the load caused by the inflation ofthe airbag to the frangible portion so that the frangible portion opens,whereby the airbag is allowed to deploy to the rear of the seat backthrough the frangible portion.

Also, according to the aspect wherein the pad member is provided with afirst slit extending from a rear of a deployment port of the airbagmodule to a front of the frangible portion, it is possible to make theairbag deploy to the rear of the seat back. Since the airbag can becovered by the pad member, the touch feeling of the rear face of thevehicle seat is improved.

Also, according to the aspect wherein the pad member is provided with asecond slit such that the first stay cloth is passed therethrough, thelength of the first stay cloth can be reduced, and therefore, the loadapplied to the first stay cloth is easily transmitted to the frangibleportion and this facilitates the opening of the frangible portion.

Also, according to the aspect wherein the second stay cloth extendsalong a lower edge and a rear edge of the pad member to reach a vicinityof the part below the frangible portion, the second stay cloth can beattached easily.

Also, according to the aspect wherein the bracket includes a rim wallprotruding forward at a lower edge thereof and a hooking member isjoined to the second stay cloth, the second stay cloth can be joined tothe bracket easily.

Also, according to the aspect wherein the bracket includes an engagementportion above the airbag module, and an engaged member engaged by theengagement portion is joined to the base end of the first stay cloth,the first stay cloth can be joined to the bracket easily.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an explanatory diagram showing deployment of an airbag of avehicle seat;

FIG. 2 is a rear view of a frame of the vehicle seat;

FIG. 3 is a rear view of the vehicle seat;

FIG. 4 is a sectional view of a vehicle seat according to the firstembodiment taken along line IV-IV in FIG. 3;

FIG. 5 is a sectional view of the vehicle seat according to the secondembodiment;

FIG. 6 is a sectional view of the vehicle seat according to the thirdembodiment;

FIG. 7 is a sectional view of a vehicle seat according to anotherembodiment, in which (A) arrangement of a second stay cloth is differentand (B) arrangement of a first stay cloth is different compared to thefirst embodiment;

FIG. 8 is a rear view of a vehicle seat according to another embodiment,in which a pad member is provided with (A) crossing two slits and (B) aslit forming a substantially H-shape;

FIG. 9 is a sectional view of a vehicle seat according to anotherembodiment provided with (A) a backboard having a thin-walled portionand (B) a backboard having a slit; and

FIG. 10 is a sectional view of a vehicle seat according to anotherembodiment, in which (A) an outer case is omitted and (B) a retainer andlid are omitted.

MODES FOR CARRYING OUT THE INVENTION

In the following, two embodiments in which a vehicle seat according tothe present invention is applied to an automobile will be described withreference to the drawings.

First Embodiment

As shown in FIG. 1, a vehicle seat 1 according to the first embodimentof the present invention constitutes a front seat in the first row of anautomobile. The seat includes a seat cushion 3 provided on a floor 2 ofthe automobile, a seat back 4 supported by a rear part of the seatcushion 3, and a headrest 5 provided on an upper part of the seat back4.

As shown in FIG. 2, the seat back 4 includes a seat back frame 7 servingas a skeleton, a pad member 8 supported by the seat back frame 7, and askin member 9 provided on a surface of the pad member 8 and forming anexterior surface of the seat back 4.

The seat back frame 7 includes a pair of left and right side frames 11extending vertically, an upper frame 12 extending laterally to be joinedto the upper ends of the left and right side frames 11, and a lowerframe 13 extending laterally to be joined to the lower parts of the leftand right side frames 11. Side frame upper parts 14 that form the upperparts of the left and right side frames 11 and the upper frame 12 areformed by bending a single circular pipe in an inverted U-shape.Further, Side frame lower parts 15 constituting the lower parts of theside frames 11 are each formed of a sheet metal member and are welded tothe respective ends of the pipe. A pair of upper and lower supportmembers 16 is provided to extend between the left and right side frames11. A plate-shaped pressure receiving member 17 for retractablysupporting the back of the occupant is joined to the front side of thesupport members 16.

As shown in FIG. 2, an upper part of the seat back frame 7 is formed bythe upper frame 12 and the left and right side frame upper parts 14 andhas a substantially trapezoidal shape in rear view.

The upper frame 12 is provided with a flat front surface 21 on a frontside of a laterally intermediate part thereof. The front surface 21 isformed by press-deforming the circular pipe so as to make the crosssection thereof semicircular. A pair of left and right pillar supportbrackets 22 are welded to the front surface 21. Each pillar supportbracket 22 is formed in a rectangular tube shape having open ends. Thepillar support bracket 22 each have an axis extending substantiallyvertically and are laterally spaced from each other. Pillar supportmembers 23 are inserted into the pillar support brackets 22,respectively. Each pillar support member 23 includes a tubular portion24 and a flange portion 25 that protrudes sideways from the upper end ofthe tubular portion 24. The axial direction of the tubular portions 24is substantially parallel with the extension direction of the sideframes 11.

The headrest 5 includes a headrest main body 27 and a pair of left andright pillars 28 projecting from the headrest main body 27. With thepillars 28 inserted into the respective tubular portions 24, theheadrest 5 is supported by the seat back frame 7 to be movable along theaxes of the tubular portions 24. Each flange portion 25 is provided withan engagement means (not shown in the drawings) for fixing the insertionposition of the pillar 28 relative to the tubular portion 24. Theheadrest 5 is fixed at a predetermined position by the engagement means.

A bracket 31 is joined to the side frames 11 and the upper frame 12. Thebracket 31 is located in an upper half of the seat back frame 7. Thebracket 31 is in a plate-like shape facing substantially in thefore-and-aft direction. The bracket 31 consists of a single plate memberformed by drawing a sheet metal and includes a plate-shaped main portion30 having a main surface facing in the fore-and-aft direction, a pair ofleft and right upper tongues 34 protruding upward from an upper edge ofthe main portion 30 in a strip shape, and a pair of left and right lowertongues 35 respectively protruding outward from the left and right lowerparts of the main portion 30. The main portion 30 is constituted of acentral part 32 forming an upper part of the main portion 30 and abottom part 33 provided below the central part 32.

The central part 32 has a substantially trapezoidal shape having anupwardly diminishing lateral width in rear view. The central part 32 hasa substantially same shape as that of the upper part of the seat backframe 7.

The upper tongues 34 protrude upward respectively from left and rightends of the upper edge of the central part 32 and are formed to belaterally spaced from each other. The upper tongues 34 are arranged tobe laterally symmetrical about the lateral center line of the seat backframe 7. The upper tongues 34 are respectively curved at upper endsthereof to extend along the rear face of the upper frame 12 and arewelded to the upper frame 12. The lower tongues 35 are curved to extendalong the rear faces of the side frame upper parts 14 and are welded tothe side frames 11, respectively. In the present embodiment, the uppertongues 34 are welded to upper parts of the rear face of the upper frame12 (parts shown by broken lines in FIG. 2) and the lower tongues 35 arewelded to left and right outer parts of the rear face of the side frameupper parts 14 (parts shown by broken lines in FIG. 2).

As shown in FIG. 4, the lower edge of the bottom part 33 is providedwith a rim wall 36 protruding forward over the entirety of the loweredge. At boundaries between the bottom part 33 and the lower tongues 35,a pair of left and right frangible portions 37 are formed. In thepresent embodiment, the bracket 31 is bent forward at the frangibleportions 37 in a U-shape. Multiple lightening holes 38 are formed atappropriate positions of the bottom part 33 to reduce the weight of thebracket 31.

The rear face of the central part 32 is formed with a recess 41 that isrecessed forward substantially at the center thereof. The bottom of therecess 41 overlaps with the side frames 11 in side view. The recess 41is defined by a recess bottom wall 42 having a flat plate-like shape andfacing substantially in the fore-and-aft direction and side wallssurrounding the recess bottom wall 42. The recess bottom wall 42 isinclined rearward in the downward direction with respect to the axialdirection of the pillars 28 in side view. The recess bottom wall 42 hasa substantially rectangular shape extending laterally in rear view, andthe recess 41 has a substantially rectangular cuboid shape.

The recess 41 houses therein an outer case 40 made of resin. The outercase 40 has a substantially rectangular cuboid shape that extendslaterally. The outer case 40 includes a bottom wall 40B facing in thefore-and-aft direction and side walls 40S surrounding the bottom wall40B. The outer case 40 is formed with a housing recess 40R defined bythe bottom wall 40B and the side walls 40S. The housing recess 40R isrecessed forward and opens rearward. At predetermined positions of theupper surface and the lower surface of the outer case 40 are providedengagement claws 40C that project outward in the vertical direction. Theupper wall and the lower wall of the recess 41 are respectively providedwith engagement holes penetrating therethrough at positionscorresponding to the engagement claws 40C to engage the engagement claws40C.

A fitting projection 40P that projects forward is provided at apredetermined position of the front face of the outer case 40, and therecess bottom wall 42 is provided with a positioning hole penetratingtherethrough at a position corresponding to the fitting projection 40P.When the outer case 40 is joined to the recess 41, the engagement claws40C are engaged with the engagement holes and the fitting projection 40Pare inserted into the positioning hole, whereby the outer case 40 can beeasily placed at an appropriate position.

An opening edge of the outer case 40 is provided with an extension 40Eextending substantially orthogonal to the side walls 40S. The extension40E extends more outward than the opening edge defining the opening ofthe recess 41 of the bracket 31. At least a part of the opening edge ofthe recess 41, preferably, the entire opening edge, is covered by theextension 40E from the rear.

An airbag module 43 is housed in the housing recess 40R. The airbagmodule 43 is in contact with the bottom wall 40B, and the airbag module43 is accommodated inside the recess 41. The airbag module 43 includesan airbag 45, an inflator 46 configured to inflate the airbag 45, and acase 47 that houses the airbag 45 and the inflator 46.

The case 47 includes a retainer 48 having a substantially rectangularcuboid shape and provided with a recess that opens rearward and a lid 49configured to close the opening of the recess.

The inflator 46 is substantially cylindrical in shape. The inflator 46is housed in the recess of the retainer 48 to be positioned in the lowerhalf of the retainer 48, more specifically in the lower front corner ofthe same, in a laterally extending manner and is joined to the retainer48. The airbag 45 is housed in the recess of the retainer 48 in a foldedstate. The airbag 45 is positioned to cover the inflator 46 from above.

The retainer 48 includes an upper wall 44 defining the recess thereof.The upper wall 44 has a downward facing surface and opposes the inflator46 vertically. The airbag 45 is positioned between the upper wall 44 andthe inflator 46.

The lid 49 is made of resin. The lid 49 includes a plate-shaped lid mainbody 49B in a substantially rectangular cuboid shape having a mainsurface facing in the fore-and-aft direction and lid engagement portions49L extending forward from upper, lower, left, and right ends of the lidmain body 49B and each having an engagement claw at an end thereof. Theupper, lower, left, and right walls of the retainer 48 are formed withrespective engagement holes, and with the engagement claws engaging thecorresponding engagement holes, the lid 49 is joined to the retainer 48.An inner side of the lid main body 49B is formed with a laterallyextending groove. The lid main body 49B has a smaller thickness at thegroove 53 than another part thereof. The groove 53 extends in thevertical direction from each of the left and right ends to the upper andlower ends of the lid main body 49B.

A hinge 49H is formed at the connection between the lid main body 49Band each lid engagement portion 49L, and the lid 49 is hinged to theupper edge and the lower edge of the opening of the retainer 48. When aload is applied to the lid 49 upon inflation of the airbag 45, the lid49 is torn open along the groove 53. Thus, the groove 53 functions as adeployment port. Once the lid 49 is torn open, the upper rear part andthe lower rear part of the lid 49 pivot with the upper edge and thelower edge being axes, respectively, so that the case 47 is opened.Since the opening edge of the recess 41 of the bracket 31 is covered bythe extension 40E from the rear, when the airbag 45 inflates, the airbag45 does not directly contact the opening edge of the recess 41 and thedamage to the airbag 45 is prevented.

The front face of the retainer 48 is provided with a male threadedportion 50 that projects forward. The bottom wall of the outer case 40and the recess bottom wall 42 are provided with through-holes 51, 44T,respectively, penetrating therethrough at a position corresponding tothe male threaded portion 50. By passing the male threaded portion 50through the two through-holes 51 of the outer case 40 and the recessbottom wall 42 and then attaching a nut 52 to the male threaded portion50, the airbag module 43 is fastened to the bracket 31 together with theouter case 40. After the fastening, the case 47 is located at a positionoverlapping with the side frames 11 in side view.

In an upper part of the central part 32 above the recess 41, a pair ofleft and right mounting holes 55 are formed to penetrate therethrough inthe thickness direction.

A blower 56 is joined to the front face of the recess bottom wall 42.The blower 56 includes a blower case 57, a motor 58 accommodated in theblower case 57, and a fan 60 joined to the rotation shaft 59 of themotor 58.

The blower case 57 has a substantially rectangular cuboid shape having asurface facing in the fore-and-aft direction. The front wall of theblower case 57 is formed with an opening. The blower case 57 is formedwith through-holes at predetermined positions thereof to penetratetherethrough in the fore-and-aft direction, and the recess bottom wall42 is formed with screw holes at positions thereof corresponding to thethrough-holes. The blower case 57 is joined substantially to the centerof the front face of the recess bottom wall 42 with respect to thelateral direction by means of screws passed through the through-holesand engaging the screw holes. The front wall of the blower case 57 issubstantially parallel with the recess bottom wall 42, and the blowercase 57 is located between the left and right pillars 28. In the presentembodiment, the width of the blower case 57 in the fore-and-aftdirection is substantially small, and the front wall of the blower case57 is located rearward of the pillars 28 in side view.

A cable (not shown in the drawings) is connected to the motor 58 forsupplying electric power from the outside of the vehicle seat 1. Themotor 58 is driven by the supplied electric power to rotate the fan 60.The rotation of the fan 60 causes air to be blown forward.

The pad member 8 is made of a flexible cushioning material such aspolyurethane foam. The pad member 8 includes a front portion 65constituting a backrest surface 64 that opposes the back of theoccupant, an upper portion 66 extending rearward from the upper edge ofthe front portion 65, side portions 67 extending rearward from the leftand right side edges of the front portion 65, and a rear portion 68extending downward from the rear end of the upper portion 66.

The front portion 65 is in a substantially rectangular plate-like shapeextending vertically and having a predetermined thickness in thefore-and-aft direction. The rear face of the front portion 65 is incontact with the front faces of the side frames 11, the upper frame 12,and the pressure receiving member 17. The front portion 65 is formedwith air passage holes 69 penetrating therethrough in the fore-and-aftdirection in front of the blower 56. The air blown from the blower 56passes through the air passage holes 69 to the backrest surface 64.

The upper portion 66 extends rearward from the upper edge of the frontportion 65 to the rear edge of the upper frame 12 in side view. Theupper portion 66 is formed with through-holes 70 vertically penetratingtherethrough at positions corresponding to the upper ends of the leftand right pillar support brackets 22. Each through-hole 70 receivestherein the corresponding pillar support bracket 22.

The side portions 67 extend rearward from the left and right side edgesof the front portion 65 along the left and right exterior surfaces ofthe side frames 11 to reach the rear faces of the side frames 11.

The rear portion 68 extends downward from the rear end of the upperportion 66 to reach the lower end of the bracket 31. The rear portion 68is formed with a first slit 71 penetrating therethrough in the thicknessdirection at a position behind the recess bottom wall 42 and, morespecifically, behind the groove 53. The first slit 71 extendssubstantially orthogonally to the recess bottom wall 42 in thepenetrating direction. As shown in FIG. 3, the first slit 71 extends inthe lateral direction from between the left side frame 11 and the leftwall of the recess 41 to between the right side frame 11 and the rightwall of the recess 41. The width of the first slit 71 in the lateraldirection is larger than the width of the recess 41 in the lateraldirection and is preferably larger than the width of the central part 32in the lateral direction.

The rear portion 68 is formed with two second slits 72 penetratingtherethrough in the thickness direction at positions behind therespective mounting holes 55. Each of the second slits 72 is preferablyinclined to approach the surface-side opening of the first slit 71 asthe second slit 72 extends rearward in the penetrating direction, Thewidth of each second slit 72 in the lateral direction is substantiallythe same as that of the mounting hole 55 in the lateral direction.

As shown in FIGS. 3 and 4, the skin member 9 is formed in a bag shape bycombining a front sheet member 75 integrally covering the surfaces ofthe front portion 65, the upper portion 66, the side portions 67, andthe rear portion 68 of the pad member 8 and a rear sheet member 76constituting the rear face of the seat back 4.

The front sheet member 75 is formed by sewing together multiple pieceseach made of a sheet member, such as a piece of cloth, leather, etc. Thefront sheet member 75 includes a front piece covering the surface of thefront portion 65, side pieces 77 covering the surfaces of the left andright side portions 67, and an upper piece 78 covering the surfaces ofthe upper portion 66 and the rear portion 68. The upper edge of thefront piece is sewn to the front edge of the upper piece 78, the leftand right side edges of the front piece are sewn to the front edges ofthe side pieces 77, and the upper edges of the side pieces 77 are sewnto the left and right side edges of the upper piece 78. The rear sheetmember 76 is formed of a rear piece 79 made of a sheet member. The rearpiece 79 has a substantially rectangular shape that extends vertically.The upper edge of the rear piece 79 is sewn to the rear end edge of theupper piece 78 to form a seam 80. The seam 80 functions as a frangibleportion configured to be broken with a smaller load compared to theother seams.

The seam 80 is located in the rear end opening portion of the first slit71. The seam 80 is located behind an upper half of the recess 41 and,more specifically, substantially behind the upper wall 44 of theretainer 48. Therefore, the seam 80 is located higher than the inflator46. The seam 80 is formed to extend laterally. The left end and theright end of the seams 80 are respectively located on the left and rightoutside of the recess 41. Preferably, the left end and the right end ofthe seam 80 are located on the left and right outside of the mainportion 30 of the bracket 31.

The upper side edges of the rear piece 79 are sewn to the upper sideedges of the side pieces 77. The lower side edges of the rear piece 79and the lower side edges of the side pieces 77 are openably joined bymeans of fasteners, touch and close fasteners, snap-fits, or the like.Thereby, the skin member 9 can be joined to the seat back 4 by puttingthe skin member 9 on the seat back frame 7 and the pad member 8 and thenjoining the rear piece 79 and the side pieces 77 to each other.

Between the bracket 31 and the skin member 9, a first stay cloth 81 anda second stay cloth 82 for restricting the deployment direction of theairbag 45 are provided. Each of the first stay cloth 81 and the secondstay cloth 82 is formed of a sheet member having a lower stretchabilitythan that of the skin member 9. One ends of the first stay cloth 81 andthe second stay cloth 82 are joined to the bracket 31 at positions aboveand below the airbag module 43, respectively. The one end of the firststay cloth 81 has a pair of left and right clips 83 attached thereto.Each clip 83 is fitted into the corresponding mounting hole 55. The oneend of the second stay cloth 82 has J-shaped hooks 84, which serve ashooking members, attached thereto. Each hook 84 is hooked to the rimwall 36. The first stay cloth 81 extends rearward from the clips 83 andpasses through the second slits 72 to reach the upper vicinity of theseam 80. The second stay cloth 82 extends rearward and then upward alongthe lower edge and the rear edge of the rear portion 68 to reach thelower vicinity of the seam 80. The other end of the first stay cloth 81and the lower edge of the upper piece 78 are sewn to each other in thevicinity of the seam 80. The other end of the second stay cloth 82 andthe upper edge of the rear piece 79 are sewn to each other in thevicinity of the seam 80.

Next, an operation of the vehicle seat 1 will be described. A forwardacceleration or load is applied to the occupant seated in the rear seatat the time of a frontal collision or the like. To detect such a loadapplied to the occupant seated in the rear seat, a sensor 92 configuredto detect the load applied to the seat belt 91 worn by the occupantseated in the rear seat may be provided, for example.

When the acceleration of the occupant seated in the rear seat or theload applied to the seat belt 91 becomes higher or equal to apredetermined value, gas is discharged from the inflator 46. The airbag45 inflating upward due to the gas discharged from the inflator 46 isguided rearward by the lower surface of the upper wall 44 of theretainer 48. Thus, the upper wall 44 of the retainer 48 functions as aguide wall for guiding the inflation direction of the airbag 45. Therearward inflation of the airbag 45 applies a load on the lid 49, andthe lid 49 is torn open at the groove 53, whereby the case 47 of theairbag module 43 is opened. The airbag 45 protrudes from the case 47 andpasses through the first slit 71 by being guided by the first stay cloth81 and the second stay cloth 82 to reach the seam 80. At this time, theseam 80 is broken by the load from the airbag 45 and an opening isformed in the skin member 9. The airbag 45 passes through the opening toprotrude from the rear face of the seat back 4, and after inflatingrearward and obliquely upward, deploys to extend downward and rearward.The airbag 45 is arched to be convex upward at the time of deployment(broken line in FIG. 1). Therefore, regardless of the distance betweenthe vehicle seat 1 and the rear seat, it is possible to cause the airbag45 to deploy to the front of the upper half of the occupant's body. Whenthe rear seat is near the vehicle seat 1, the airbag 45 is bent so thatthe rearward load applied to the occupant by the deployment of theairbag 45 can be reduced.

Next, effects of the vehicle seat 1 will be described. As shown in FIG.4, the airbag module 43 is covered by the skin member 9 and is locatedinside the seat back 4. Since the airbag module 43 is not exposed to therear face of the seat back 4, the aesthetic appearance of the vehicleseat 1 can be improved. Further, since the airbag module 43 is coveredby the pad member 8, the touch feeling of the rear face of the vehicleseat 1 is improved.

Since the airbag module 43 is housed in the recess 41, an amount ofprotrusion of the airbag module 43 from the rear face of the seat back 4can be reduced. The front part of the case 47 of the airbag module 43 islocated at a position below the upper frame 12 and overlapping with theside frames 11 in side view. Thus, compared to a case where the case 47as a whole is located in the rear of the side frames 11, the airbagmodule 43 is located more forward relative to the seat back frame 7.Therefore, an amount of rearward protrusion of the seat back 4 can bereduced.

The airbag 45 is caused to inflate along the first slit 71 by the gasfrom the inflator 46. The inflation applies an upward load to the firststay cloth 81 and a downward load to the second stay cloth 82. The loadsapplied to the first stay cloth 81 and the second stay cloth 82 aretransmitted to the seam 80, the parts of the skin member 9 in the uppervicinity and the lower vicinity of the seam 80 are pulled upward anddownward, respectively, so that the seam 80 is opened. The airbag 45passes through the first slit 71 and the opened seam 80 to deploy to therear of the seat back 4.

Owing to the formation of the second slits, the first stay cloth 81 canbe arranged to extend substantially linearly from the rear of themounting holes 55 to the front of the seam 80. This can reduce thelength of the first stay cloth 81 in the fore-and-aft direction.Therefore, the load applied to the first stay cloth 81 is easilytransmitted to the seam 80 and this facilitates the opening of the seam80.

The second stay cloth 82 extends along the lower edge and the rear edgeof the pad member 8 to reach the vicinity of the lower part of the seam80. Therefore, after the pad member 8 and the skin member 9 areassembled together and the seat back frame 7 is covered with theassembly, the hooks 84 can be hooked to the rim wall 36 from below.Thus, the attachment of the second stay cloth 82 is easy.

The first stay cloth 81 is provided with the pair of clips 83 and thefirst stay cloth 81 can be joined to the bracket 31 easily by insertingthe clips 83 to the mounting holes 55, respectively. Also, since thefirst stay cloth 81 is joined to the two mounting holes 55 arranged inthe lateral direction, an area of the first stay cloth 81 for receivingthe load due to the inflation of the airbag 45 is widened in the lateraldirection, whereby the load due to the inflation of the airbag isapplied to the seam 80 even more easily.

The one ends of the first stay cloth 81 and the second stay cloth 82 areengaged by parts of the bracket 31 in the vicinity of the airbag module43, and therefore, the load can be easily transmitted to the first staycloth 81 and the second stay cloth 82. Also, the first stay cloth 81 andthe second stay cloth 82 allows the load due to the deployment of theairbag 45 to concentrate on the seam 80, whereby the seam 80 can bebroken reliably at the time of deployment of the airbag 45.

The airbag 45 inflates rearward relative to the recess 41. The seam 80overlaps with the recess 41 at the central part thereof in rear view,and therefore, the airbag 45 inflating rearward can pass the seam 80easily.

The seam 80 (frangible portion) is located below the upper frame 12, andtherefore, the load applied to the skin member 9 due to the inflation ofthe airbag 45 is easily transmitted to the seam 80 (frangible portion)and this facilitates the opening of the seam 80 (frangible portion).With at least a part of the seam 80 (frangible portion) overlaps withthe recess 41 in rear view, the airbag 45 is allowed to pass the seam 80(frangible portion) easily. Further, in the case where the seam 80(frangible portion) overlaps with the upper half of the recess 41 inrear view, the airbag 45 can deploy rearward from a higher part of theseat back 4.

As shown in FIG. 3, the seam 80 extends laterally on the rear face ofthe seat back 4. Therefore, the width of the airbag 45 in the lateraldirection (lateral width) at the time of deployment can be made largeand a wide range of lateral positions of the occupant seated in the rearseat can be dealt with. Further, the left end and the right end of theseam 80 are respectively located on the left and right outside of therecess 41, and preferably, the left end and the right end of the seam 80are respectively located on the left and right outside of the mainportion 30 of the bracket 31. Thus, owing to the enlarged lateral widthof the seam 80, the airbag 45 inflating rearward can pass through theseam 80 easily. Also, the lateral width of the airbag 45 at the time ofdeployment can be made large and a wider range of lateral positions ofthe occupant seated in the rear seat can be dealt with.

That is, since the lateral width of the seam 80 (frangible portion) islarger than the lateral width of the recess 41 in rear view, the airbag45 can pass through the seam 80 (frangible portion) more easily. Also,the lateral width of the airbag 45 at the time of deployment can be madelarger.

It is conceivable to join the airbag module to the seat back frame byproviding an airbag case for supporting the airbag module, fastening theairbag case to the side frames at left and right edges of a lower endthereof, and hooking an upper end center of the airbag case to aprojection provided on the upper frame. In this case, when the airbagdeploys rearward, a forward load is applied to the airbag case. Sincethe upper part of the airbag case is hooked to the upper frame at theupper end center thereof, there is a problem that the rotation of theupper part of the airbag case may not be sufficiently restricted and thedeployment direction of the airbag may become unstable.

However, in the present embodiment, as shown in FIG. 2, the bracket 31is joined to the upper frame 12 at the left and right upper tongues 34in a laterally spaced relationship. Therefore, the rotation of the upperpart of the bracket 31 about an axis extending in a substantiallyvertical direction is restricted. Thus, the bracket 31 is not separatedfrom the seat back frame 7 easily and the joint between the bracket 31and the seat back frame 7 can be made stronger.

Since the bracket 31 is constituted of a single plate member, thebracket 31 can be light in weight and low in cost. The bracket 31 is ina substantially trapezoidal shape with an upper side being a short sideand is substantially identical in shape with an upper part of the seatback frame 7. Therefore, the upper tongues 34 and the lower tongues 35can be made short. Further, the upper right corner and the upper leftcorner of the bracket 31 are cut, the weight of the bracket 31 isreduced.

A forward load is applied to the bracket 31 by deployment of the airbag45 or collision of the occupant seated in the rear seat. Since the uppertongues 34 are disposed to extend along the rear face of the upper frame12 and the lower tongues 35 are disposed to extend along the rear faceof the side frame upper parts 14, a rearward load is applied to theupper tongues 34 and the lower tongues 35 from the rear face of theupper frame 12 and the rear face of the side frame upper parts 14.Therefore, the bracket 31 can be supported by the seat back frame 7 andresist against the forward load.

The airbag module 43 is fastened to the recess bottom wall 42. At thetime of deployment of the airbag 45, a forward load is applied to theairbag module 43. Because the airbag module 43 is fastened to the recessbottom wall 42, the bracket 31 resists against the load and the airbagmodule 43 is supported by the bracket 31. Also, since the airbag module43 is fastened to the recess bottom wall 42, the airbag module 43 can befastened to the bracket 31 easily.

The airbag module 43 is located in the upper half of the seat back frame7. Therefore, the airbag module 43 is located in front of the upper bodyof the occupant seated in the rear seat, whereby the airbag 45 candeploy to the front of the upper body of the occupant seated in the rearseat to protect the upper body of the occupant seated in the rear seat.Further, since the seam 80 is located behind the upper part of therecess 41, the airbag 45 can deploy from a higher part of the seat back4.

The bracket 31 is located rearward of the pillars 28. Therefore, it ispossible to attach the bracket 31 without changing the position of thepillars 28.

A load applied when the occupant is seated may cause the back of theoccupant to move to the rear of the axes of the pillars 28. In this casealso, since the recess bottom wall 42 is inclined rearward in thedownward direction, the recess bottom wall 42 does not interfere withthe back of the occupant and the discomfort felt by the occupant can bereduced. Further, because the bracket 31 is located above the pressurereceiving member 17, it is possible to prevent the bracket 31 fromcausing discomfort felt in the back of the occupant.

The bottom part 33 laterally connects the side frames 11 via the lowertongues 35, and thus, functions as a cross member increasing thestiffness of the seat back frame 7. To increase the stiffness of theseat back frame 7, preferably, the bottom part 33 is joined to a part ofeach side frame 11 apart from the upper end of the side frame 11 by5-20% of the entire length of the side frame 11. In a case where theside frames 11 are formed with bent portions 93 that are bent laterallyinward, the bottom part 33 is preferably joined to the side frames 11 atpositions above the bent portions 93.

The stiffness of the bottom part 33 is improved by the rim wall 36.Since the lower wall defining the recess 41 and the rim wall 36 opposeeach other and the lower part of the bracket 31 has a channel shape thatopens forward in side view, the stiffness is further improved. Theimprovement of the stiffness of the lower part of the bracket 31 makesthe joint between the side frames 11 strong, whereby the stiffness ofthe seat back frame 7 is improved even further.

The provision of the blower 56 in the vehicle seat 1 allows air to beblown from the air passage holes 69 of the seat back 4 toward the seatedoccupant, whereby the sitting comfort can be improved. Because theblower 56 is joined to the bracket 31 supporting the airbag 45, there isno need to provide a bracket 31 for supporting the blower 56, wherebythe number of components is reduced and the vehicle seat 1 can be madesimple.

Also, when the airbag 45 deploys, the occupant seated in the rear seatmay collide with the airbag 45 so that a forward load is applied to thebracket 31. At this time, the frangible portions 37 of the bracket 31can deform to absorb the forward load applied to the bracket 31.Therefore, it is possible to reduce the load applied to the occupantseated in the rear seat. Further, it is possible to prevent thecollision of the occupant seated in the rear seat from applying a loadto the occupant of the vehicle seat 1.

Second Embodiment

The vehicle seat 1 according to the second embodiment differs from thefirst embodiment in that, as shown in FIG. 5, the airbag module 43 isfastened to a recess lower wall 96 defining a lower part of the recess41 and facing in the vertical direction. The male threaded portion 50provided on the airbag module 43 extends downward. The recess lower wall96 is provided with a through-hole 51 at a position corresponding to themale threaded portion 50. One side wall 40S of the outer case 40 isprovided with a through-hole 40T at a position corresponding to the malethreaded portion 50. By passing the male threaded portion 50 through thethrough-holes 51, 41T and joining the nut 52 to the male threadedportion 50, the airbag module 43 is fastened to the recess lower wall96. The airbag module 43 may be fastened to any of the side wallssurrounding the recess bottom wall 42.

The airbag 45 is configured to deploy upward and rearward of the seatback 4, and therefore, at the time of deployment of the airbag 45, aload may be applied to the recess 41 in the downward direction. With theairbag module 43 fastened to the recess lower wall 96, the bracket 31can resist against the downward load at the time of deployment. Inaddition, because the male threaded portion 50 does not protrudeforward, the discomfort felt in the back of the seated occupant can bereduced.

Third Embodiment

The vehicle seat 1 according to the third embodiment differs from thefirst embodiment in that, as shown in FIG. 6, the second slits 72 arenot provided and only the arrangement of the first stay cloth 81 and thesecond stay cloth 82 is changed. The first stay cloth 81 is fixed to themounting holes 55 by the clips 83 at one end thereof and extendsdownward along a reverse side of the pad member 8 to reach the seam 80through the first slit 71. The second stay cloth 82 is hooked to the rimwall 36 by the hooks 84 on one end thereof and extends upward along thereverse side of the pad member 8 to reach the seam 80 through the firstslit 71. In this arrangement also, the first stay cloth 81 and thesecond stay cloth 82 restrict the deployment direction of the airbag 45from above and below, respectively, the deployment direction of theairbag 45 is controlled to be directed toward the seam 80.

Concrete embodiments of the present invention have been described in theforegoing but the present invention is not limited to the aboveembodiments and may be modified or altered in various ways. For example,the shape of the bracket 31 is not limited to that shown in the aboveembodiments and may be changed as appropriate. In the above embodiments,the second stay cloth 82 was hooked to the rim wall 36 of the bottompart 33 but may have clips fitted into the lightening holes 38, forexample. In the above embodiments, the vehicle seat 1 was provided withthe first stay cloth 81 and the second stay cloth 82 but an embodimentin which either one of the first stay cloth 81 and the second stay cloth82 is provided may be possible. Also, a modification may be made to thefirst embodiment such that only the second stay cloth 82 extends along areverse side of the pad member 8 as shown in (A) of FIG. 7 or only thefirst stay cloth 81 extends along the reverse side of the pad member 8as shown in (B) of FIG. 7.

In the above embodiments, the seam 80 was formed to extend laterally onthe rear face of the seat back 4 but it is possible to divide each ofthe side pieces 77 to upper and lower parts and to provide the left andright ends of the seam 80 on the left and right exterior surfaces of theside portions 67 so that the seam 80 extends laterally between the leftand right side faces of the seat back 4 via the rear face.

Also, in the above embodiments, the first slit 71 was formed in the padmember 8 to extend laterally, but the present invention is not limitedto this embodiment. The pad member 8 may be provided with a third slit100 that intersects with the first slit 71 ((A) of FIG. 8). Further,third slits 101 may be provided at respective ends of the first slit 71such that each third slit 101 extends upward and downward from thecorresponding end ((B) of FIG. 8). The provision of the third slits 100,101 makes the pad member 8 easier to open from the first slit 71,thereby to shorten the time required for the airbag 45 to deploy.

Also, in the above embodiments, the rear face of the seat back 4 wasprovided with the rear sheet member 76 made of a sheet member but, asshown in (A) of FIG. 9, instead of the rear sheet member 76, it may beprovided with a backboard 110 made of resin or the like. The backboard110 is formed in a plate-like shape having a main surface facing in thefore-and-aft direction. The upper end of the backboard 110 is bentrearward as it extends upward along the rear portion 68. The backboard110 is supported by the side frames 11. The upper part of the backboard110 is formed with a thin-walled portion 111 having a smaller thicknesssuch that the thin-walled portion 111 extends laterally in rear view.The thin-walled portion 111 is preferably formed substantially behindthe groove 53 of the airbag module 43. When the airbag 45 deploys, aload is applied to the backboard 110 from the airbag 45. The load causesthe backboard 110 to be bent rearward at the thin-walled portion 111.The bending of the backboard 110 creates a gap between the backboard 110and the skin member 9 covering the rear portion 68. The airbag 45deploys rearward of the seat back 4 rearward through the gap.

Also, as shown in (B) of FIG. 9, a backboard 120 having a slit 121configured to be torn open by the load applied from the airbag 45 at thetime of deployment of the airbag 45 may be provided. The slit 121 islocated behind the airbag module 43. The slit 121 may be a groove formedin the front face of the backboard 120. The slit 121 preferably includesa part extending laterally and parts extending upward and downward fromeither end of the laterally extending part to form a substantiallyH-shape in rear view. When the airbag 45 deploys, the backboard 120 isbent rearward at the laterally extending part so that an opening isformed in the backboard 120. The airbag 45 deploys rearward of the seatback 4 through the opening.

Also, in the above embodiments, the outer case 40 was provided in therecess 41 but, as shown in (A) of FIG. 10, it is also possible toprevent damage to the airbag 45 at the time of inflation by enlargingthe curvature of the opening edge 130 of the recess 41. Further, asshown in (B) of FIG. 10, it is possible to fit the outer case 40 in therecess 41 and to house the airbag 45 and the inflator 46 in the housingrecess 40R of the outer case 40.

Glossary

-   1: vehicle seat-   3: seat cushion-   4: seat back-   7: seat back frame-   8: pad member-   9: skin member-   11: side frame-   12: upper frame-   17: pressure receiving member-   28: pillar (headrest pillar)-   31: bracket-   34: upper tongue-   35: lower tongue-   36: rim wall-   41: recess-   42: recess bottom wall-   43: airbag module-   44: upper wall (guide wall)-   45: airbag-   41: recess-   42: recess bottom wall-   53: groove (deployment port)-   55: mounting hole (engagement portion)-   56: blower-   50: male threaded portion (fastener)-   51: through-hole-   55: mounting hole-   71: first slit-   72: second slit-   80: seam (frangible portion)-   81: first stay cloth-   82: second stay cloth-   83: clip (engaged member)-   84: hook (hooking member)-   96: recess lower wall

The invention claimed is:
 1. A vehicle seat provided with a seat cushionand a seat back, wherein the seat back comprises: a seat back frameincluding a pair of left and right side frames extending in a verticaldirection and an upper frame connecting upper ends of the side frames toeach other; an airbag module supported to an upper half of the seat backframe via a bracket; and a skin member covering the seat back frame, thebracket, and the airbag module from a rear side thereof, wherein a partof the skin member corresponding to the airbag module is provided with afrangible portion configured to open upon inflation of an airbag,wherein the bracket is located more rearward than a headrest pillar,wherein the bracket consists of a plate member defining a recess forhousing the airbag module, and a bottom wall of the recess has a flatplate-like shape inclined rearward in a downward direction with respectto an axial direction of the headrest pillar, and wherein the bracket isjoined to the upper frame at an upper edge thereof and is joined to therespective side frames at left and right edges thereof.
 2. The vehicleseat according to claim 1, wherein the airbag module is located at aposition below the upper frame and overlapping with the side frames inside view.
 3. The vehicle seat according to claim 1, wherein a loweredge of the bracket is provided with a rim wall that protrudes forward,and the bracket is joined to the side frames at a part of the bracketbetween the rim wall and a lower end of the recess with respect to avertical direction.
 4. The vehicle seat according to claim 1, wherein anupper edge of the bracket is provided with a pair of upper tonguesprotruding in a laterally spaced relationship, and upper ends of theupper tongues are joined to the upper frame.
 5. The vehicle seataccording to claim 1, wherein the bottom wall of the recess is formedwith a through-hole and the airbag module is fastened to the bottom wallof the recess by a fastener passed through the through-hole.
 6. Thevehicle seat according to claim 1, wherein a lower side wall of therecess is formed with a through-hole and the airbag module is fastenedto the lower side wall of the recess via a fastener passed through thethrough-hole.
 7. The vehicle seat according to claim 1, wherein thebracket is located above a pressure receiving member configured tosupport a back of an occupant.
 8. The vehicle seat according to claim 1,wherein a blower for blowing air is provided on a front face of thebracket.
 9. The vehicle seat according to claim 1, wherein the airbagmodule includes the airbag, an inflator disposed below the airbag andconfigured to inflate the airbag, and a retainer that houses the airbagand the inflator and opens rearward, the retainer includes a guide wallthat opposes the inflator at a position above the airbag and facesdownward, and the airbag is guided by the guide wall to inflaterearward.
 10. The vehicle seat according to claim 9, wherein thefrangible portion is located substantially behind the guide wall. 11.The vehicle seat according to claim 9, wherein at least a part of thefrangible portion overlaps with the bracket in rear view and the airbagmodule is provided on a rear face of the bracket.
 12. The vehicle seataccording to claim 1, wherein the frangible portion extends laterally,and at least one of a first stay cloth having a base end joined to thebracket at a position above the airbag module in side view and a freeend joined to a vicinity of a part of the skin member above thefrangible portion and a second stay cloth having a base end joined tothe bracket at a position below the airbag module in side view and afree end joined to a vicinity of a part of the skin member below thefrangible portion is provided.
 13. The vehicle seat according to claim12, wherein a pad member provided at a rear of the airbag module islocated between the airbag module and the skin member, and the padmember is provided with a first slit extending from a rear of adeployment port of the airbag module to a front of the frangibleportion.
 14. The vehicle seat according to claim 13, wherein the padmember is provided with a second slit extending from a rear of a jointbetween the bracket and the base end of the first stay cloth to thefront of the frangible portion such that the first stay cloth is passedtherethrough.
 15. The vehicle seat according to claim 14, wherein thesecond stay cloth extends along a lower edge and a rear edge of the padmember to reach a vicinity of the part below the frangible portion. 16.The vehicle seat according to claim 12, wherein the bracket is in aplate-like shape having a main surface facing rearward and includes arim wall protruding forward at a lower edge thereof, and a hookingmember hooked by the rim wall is joined to the base end of the secondstay cloth.
 17. The vehicle seat according to claim 16, wherein thebracket includes an engagement portion above the airbag module, and anengaged member engaged by the engagement portion is joined to the baseend of the first stay cloth.
 18. A vehicle seat provided with a seatcushion and a seat back, wherein the seat back comprises: a seat backframe including a pair of left and right side frames extending in avertical direction and an upper frame connecting upper ends of the sideframes to each other; an airbag module supported to an upper half of theseat back frame via a bracket; and a skin member covering the seat backframe, the bracket, and the airbag module from a rear side thereof,wherein a part of the skin member corresponding to the airbag module isprovided with a frangible portion configured to open upon inflation ofan airbag, wherein the airbag module includes the airbag, an inflatordisposed below the airbag and configured to inflate the airbag, and aretainer that houses the airbag and the inflator and opens rearward, theretainer includes a guide wall that opposes the inflator at a positionabove the airbag and faces downward, the airbag is guided by the guidewall to inflate rearward, and wherein the frangible portion is locatedsubstantially behind the guide wall.
 19. A vehicle seat provided with aseat cushion and a seat back, wherein the seat back comprises: a seatback frame including a pair of left and right side frames extending in avertical direction and an upper frame connecting upper ends of the sideframes to each other; an airbag module supported to an upper half of theseat back frame via a bracket; and a skin member covering the seat backframe, the bracket, and the airbag module from a rear side thereof,wherein a part of the skin member corresponding to the airbag module isprovided with a frangible portion configured to open upon inflation ofan airbag, and wherein a blower for blowing air is provided on a frontface of the bracket.